The instant invention relates to apparatus for stacking of documents, and more particularly to an automatic stacker for stacking filled envelopes which may carry ink on their surfaces that has not completely dried.
Stacking devices are well known for taking singulated items and forming them into stacks or columns. Stackers are commonly used in conjunction with mailing machines, folders, folder/sealers, small envelope inserting devices, mail openers, envelope printers and labelers. In many of these applications, such as mailing machines and envelope printers, an envelope is imprinted with an address and then immediately fed into a stacker. Because the printing devices applying the ink to the envelopes are able to operate at speeds previously not attainable (because of new technologies, such as ink jet and laser jet printing), the ink on the envelope is not always dry as it enters the stacker. Failure of the ink to dry enables a successive envelope to smear the ink on the previous envelope in the stacker.
Accordingly, the instant invention provides an automatic stacker that can function autonomously and can be used with mailing machines, folders, folder/sealers, small envelope inserting devices, mail openers, envelope printers, labelers, etc. The automatic stacker of the instant invention accumulates paper documents or envelopes into a compact stack and prevents successive documents or envelopes from wiping over previous documents or envelopes so that printed matter will not be smeared. Moreover, the automatic stacker of the instant invention extends drying time for printed documents or envelopes before they contact the stack.